New concepts in organ site research on medulloblastoma: genetics and genomics

Medulloblastoma is the most common solid tumor in childhood, developing in the cerebellum, a hindbrain structure with origins from two distinct germinal zones. Therefore, medulloblastoma tumors show a diversity of signaling abnormalities and stem cell biologies. Sonic Hedgehog and Wnt pathways drive a substantial fraction of tumors; however, genetic pathways underlying the most aggressive subset of these tumors remain uncharted. The speakers of this session discussed the genetic diversity of both tumors and metastases, including forward genetic screens, molecular classifications and stem cell biology. They also addressed novel signaling pathways, mouse models and biomarkers, and clinical progress in targeting inappropriate activation of Shh signaling.